ad

1. an advertisement.

   the latest television lager ad

mid 19th century: abbreviation.

noun

short for advantage.

1. denoting motion or direction to.

   advance

   adduce

from Latin ad ‘to’; in the 16th century the use of ad- and its variants was extended to replace a- from a different origin such as Latin ab- (e.g. advance, from French avancer based on late Latin abante ‘in front’).

1. (forming nouns) in collective numerals.

   myriad

   triad

2. (forming nouns) in names of females in classical mythology.

   dryad

   naiad

3. (forming nouns) in names of poems and similar compositions.

   Iliad

   jeremiad

4. (forming nouns) in names of members of some taxonomic groupings.

   bromeliad

from the Greek ending -as, -ad- .

suffix

forming nouns such as ballad, salad.

from French -ade .

abbreviation, adverb

Anno Domini (used to indicate that a date comes the specified number of years after the traditional date of Christ's birth).

1. analogue to digital.

   an A/D converter